Vitali Klitschko doesn't flinch when the spectre of his worst moment in the ring is invoked with casual brutality. His interrogator wants to know if he had dared to look into the mirror to inspect the long horrific wound decorating his left eye after Lennox Lewis had launched a savage, desperate attack in their fight in Los Angeles 18 months ago.

Vitali Klitschko doesn't flinch when the spectre of his worst moment in the ring is invoked with casual brutality. His interrogator wants to know if he had dared to look into the mirror to inspect the long horrific wound decorating his left eye after Lennox Lewis had launched a savage, desperate attack in their fight in Los Angeles 18 months ago.

"It was horrible, but no one should have doubted that I would have carried on if the doctor had let me," Klitschko said. "I'm a fighter, and if you are a real man being marked for life is not a tragedy."

The man Britain's Danny Williams challenges for the World Boxing Council's heavyweight title - the crown once worn by Muhammad Ali - here on Saturday night goes on to insist that he is haunted by only one potential flow of blood. It is the one he fears might still come on to the streets of his native Ukraine.

That concern last week came as close as a mile or two of Los Angeles airport to stopping the big fight. "You look at the two things, a world heavyweight title fight, which is my business, and the future of my country and when you do that you have to think what is best for your people," adds Klitschko.

"But I had a call from Viktor Yuschenko [the leader of the successful outcry for a new, clean election] and he thanked me for my support and said that I would be more use to the cause as the world heavyweight champion. He told me to stay here and do the thing that has already brought a lot of pride to the country at a difficult time.

"I had to listen to that but I did come very close to breaking camp... my heart said that I should be at home."

Home? Most of the time now it is the Lotus Land of southern California, a big house and sweeping gardens - another planet from the ice-bound, tense streets of Kiev. But that question of his most basic loyalties has already been heavily addressed. When he fought Lewis - and announced himself as the world champion's authentic heir after leading on all scorecards until the fight was stopped after six rounds on account of that sickening latticework of torn flesh around his eye - he was asked how it was to be a new American in the land of the rich and the free.

"I live in America because I'm a professional fighter and, yes, it is a good life, but never think that I will not be Ukrainian until the day I die," he said. "Ukraine is my blood and my life - no-one must doubt that."

That was the message he sent last week with his brother and fellow heavyweight fighter, Wladimir, along with another assurance that he was putting himself at the service of the revolutionary movement.

While Wladimir, who is now back in the fight camp here, made a nightly report from the streets of Kiev, his brother anxiously surfed the American news channels either side of his time in the gym. And he said, "It is painful to hear or read the news about it. They [foreign reporters] speak about my country as though it is a banana republic. But it has a great history and 48 million people. The point is that there is a lot at stake for the whole world.

"What is happening is that people are saying how desperate they are for reform. In the East, the people are mostly former communists and they don't want to change that much. But we have to change. My father was a colonel in the Russian air force. We disagree about the direction in which the country must go. But I talk with him about it. Both sides talking... that is the key.

"Look at those demonstrators in the streets of Kiev. They didn't go to work. They didn't get paid. They just stood for what they believe. They stood in the streets for their children and the children their children will have one day. See them: no alcohol, no guns, no blood. They stand for freedom and liberty.

"I'm afraid every day and I hope nobody picks up a gun. I want so much for my country to change democratically. The old rules must go. The people don't want things that way. Under the Russians it was simply brainwashing. But if we can do it peacefully, then what an example we can set the world."

It is put to Klitschko, who has a PhD in sports science and philosophy, that as almost certainly the brainiest heavyweight champion since the bookish Gene Tunney tamed the ferocious railroad rider Jack Dempsey, he too can be a force for good in his embattled sport.

"That would never be for me to comment on," he says. "Every champion has to do his best, and then it is for the people to judge. I just know boxing is a great sport that should not live under the shadow of some bad guys."

At 6ft 7in and 18 stone, he looks as perfectly proportioned working in the gym at the Mandalay Bay casino hotel as he does in his designer sports suit. He says that the drama that is unfolding in his homeland will not distract him from the task against Williams, and he smiles serenely when he is told that the enemy camp is saying that he is a stiff, robotic fighter who will inevitably succumb to their man's superior natural talent.

"They are right about my style," he says. "Yes, it is ugly, but it is effective - and it will never have been more effective than against Danny Williams. Yes, I respect him, and I know he is saying that he has new confidence after beating Mike Tyson. But we have been looking down through his career, and we do not see anything to fear."

Some believe that Klitschko might have ebbed a little since the high water mark of the Lewis performance. They say he looked a little apprehensive when he won the vacant title against South African Corrie Sanders, a golf fanatic who appeared to have spent much of his preparation on the course rather than on the road and in the gym. But Klitschko is dismissive of all doubts, pointing out that after taking a heavy early shot from Sanders, he proceeded to cruise comfortably to an eight-round TKO. "I have proved myself the true champion," he insists.

He says it with such authority you wonder about the odds against him one day becoming president of the Ukraine. He is 4-1 on to win the fight. On the other matter, and on current form, Vegas is not likely to be much more generous.